The best time to buy and sell stock is added in DP section with annotations and test cases done(TheAlgorithms#7104)

Author: YashKesh

dynamic_programming/best_time_to_buy_sell_stock.py

@@ -82,7 +82,7 @@ def test_maxprofit(self):
         assert s.maxprofit(prices2, fee2) == 6
 
 
-def main():
+def main()->None:
     """
     This is the function for taking input and output.
     """